android 通过广播监听网络连接状况

首先添加以下权限

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

new一个广播NetStateChangeBroadcast

package aviationboss.broadcast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo.State;
import android.util.Log;
import android.widget.Toast;
import aviationboss.data.SystemData;

public class NetStateChangeBroadcast extends BroadcastReceiver {
    private ConnectivityManager connectivity;
    private boolean isConnect = false;

    @Override
    public void onReceive(Context arg0, Intent arg1) {
        // TODO Auto-generated method stub
        connectivity = (ConnectivityManager) arg0
                .getSystemService(arg0.CONNECTIVITY_SERVICE);
        State wifiState = connectivity.getNetworkInfo(
                ConnectivityManager.TYPE_WIFI).getState();
        if (State.CONNECTED == wifiState) {
            isConnect = true;
        }
        
        if(connectivity.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)!=null){
            State mobileState = connectivity.getNetworkInfo(
                    ConnectivityManager.TYPE_MOBILE).getState();
            if (State.CONNECTED == mobileState) {
                isConnect = true;
            }
        }
        
        Intent intent = new Intent();
        intent.setAction("netConnect");

        if (isConnect) {
            if (!SystemData.NetState) {
                Toast.makeText(arg0, "网络已连接", Toast.LENGTH_SHORT).show();
                SystemData.NetState = true;
                intent.putExtra("netActions", "网络已连接");
                arg0.sendBroadcast(intent);
            }
        } else {
            if (SystemData.NetState) {
                Toast.makeText(arg0, "网络已断开", Toast.LENGTH_SHORT).show();
                SystemData.NetState = false;
                intent.putExtra("netActions", "网络已断开");
                arg0.sendBroadcast(intent);
            }
        }
    }
}

判断wifi的连接状态

connectivity.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState()

判断移动网的连接状态

connectivity.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState()

在配置文件中添加该广播，并设置监听的动作

<receiver android:name="aviationboss.broadcast.NetStateChangeBroadcast" >
    <intent-filter>
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
    </intent-filter>
</receiver>